Printing

As you can see I've been printing some things off I have been raiding Thingiverse for test pieces, mainly using http://www.thingiverse.com/thing:1216 its a really detailed model I've had some excellent results printing, I am really happy with the quality of the prints I am getting, but there's still some tweaking to go (there always will be)

This is the current state of my workbench, features include state of the art material metering system, advanced climate control and clean layout of components.

So while working on my design I decided to use leadscrews mainly because they are accurate and easy to implement (on a small scale) and they work great, however the sacrifice in speed (due to the power of the motors) is significant. Another negative impact the leadscrews have in my design is vibrations.

The installation in my deign is a bit.. well crappy. In professional machines a leadscrew is held in place with bearings and rotated or the leadscrew is clamped solid and the motor is clamped to the axis and pulls the axis up and down the leadscrew. Due to the fact that I do no have access to a workshop I am limited in what I can build and the accuracy of the things I can build. So I don't have the motors perfectly lined up with the leadnuts there are eccentricities which are unnoticeable in all the axis except the the x-axis which causes a pronounced vibration when trying to move at medium to high speeds.

2 Solutions present themselves constraining the leadscrew with bearings or swapping out to belts. Recently I have discovered a new supplier of reprap supplies in Australia; Builby CNC they have and excellent supply of materials and parts I will be ordering a couple of pulleys and some belt for the X and Y axis on my machine I can manufacture the parts I need to mount the motors and clamp the belt etc then install the new drive system, this will eliminate the vibrations and maybe give me an increase in speed aswell. 

So the project moves on, now I have a working 3D printer I will use it to improve itself

I'm back

I went on holiday for 2 weeks now i'm back more up dates coming soon did a whole bunch of work right before I left here is a picture

Frame complete and power supply.

On Thursday I received the screws I needed from e-bay this allowed me to just about finish the frame of the machine, I still need to mount the rails onto the frame, here is a picture of frame:

I've also decided to use an ATX power supply to power the whole thing, I had 300watt supply spare and its capable of supplying 18A on the 12v rail which is 2 more than suggested on the reprap wiki. I followed this page on the wiki to modify it for use as a power supply for the machine.

On the inside I nstalled a switch that turns the power supply on and off trimmed all the wires off the usual mother board 24 pin connector, the big white thing near the fan is a load resistor on the 5v line which is recommended on the wiki to stop the supply from tripping out.

Here's the finished supply everything appears to work after testing, in this picture you can see I left one string of molex connectors on in order to power some fans which I may use for cooling the parts as they are printed. You can also see the fuses I added after a suggestion by a friendly Jaycar dude, on the two twelve volt lines that I am using to power the electronics.

Fabrication start

Been a little while since I have updated but the project has leapt forward.

The previous post promised pictures of my frame so here you go:

This picture does not include details such as the motors or the lead-crews.

With this design I have tried to make it as easy as possible to construct, the frame is entirely made from aluminium extrusions which are easy to work with and are fairly cheap.

I tired to find multiple suppliers of the various extrusions that I need but seems like very few want to deal with the public so I ended up buying the aluminium that I needed from Bunnings I didn't think it was too expenisve but I have little to compare it against.

All the parts for the prototyper have been ordered from all over the planet, shipping is painful. I managed to order the linear bearings and rods from a Melbourne supplier, the lead-screws are coming from the UK, electronics from the US and nuts and bolts from China. Yes that's right I had to order fasteners from outside the country via ebay as so many places are just blatantly ripping people off.

I received the extruder from makergear yesterday and spent yesterday and this morning building it from the kit, everything went fairly painlessly though my soldering skills still need a bit of work. I was really impressed with the spare parts provided with the kit and assembling it myself gave me a better idea of how the whole thing goes together and works which will make it easier to fix when something goes wrong.

Here is some pics of the Plastruder going together:

This is the hot end it contains the heating element, the nozzle and tube for the filament to travel down as well as the therm-resistor for the electronics to maintain the temperature.

This is the complete assembly, hot end inserted into the filament drive which is driven by the stepper motor. The filament drive consists of a ball-bearing held against a gear by the 4 springs you can see below.

I have also started working on the frame, lots of holes to drill it doesn't make good pictures until I start assembling it.

I have yet to receive to the lead-screws or the control electronics yet, I'm really keen to get the lead-screws as I want to know that they will fit the lead-nuts I have ordered (and received) from the US I am also a little worried about the linear speed the lead-screws can produce, I may need to use beefier motors.

Frame Materials

I have got a frame layout that works well, and that I should be able to produce without a workshop, Ill put some pictures up online tomorrow. 

My initial  plan was to construct a timber frame however after a trip to Bunnings aluminium angle seems like the material of choice its quite cheap and I have familiarity with it. I may still use some timber for the base of the machine then use aluminium for the load bearing parts.

Next stage is to check online for more angle suppliers that may have better geometries or cheaper prices than Bunnings then hit the CAD and finalise the design using aluminium angle so when I buy the matrial I will know exactly what size to cut each piece.

Budget

Trying to work to a budget of around $1000, its going to be tight

Electronics from Makerbot come to around $700, thats the MK7 extruder head, Mk4 electronics, motors, heated bed, 1kg of plastic fibre and some heatproof tape needed to construct the extruder head.

At the moment i'm finalising the design of the machine itself, although at the minimum i'll be needing 6 rails and 6 bearings to run on them. Sourced form Ebay the set comes to about $140

I've decided to use acme leadscrews to provide the linear motion there is a company in America that provides the screws machined with matching nuts, also coupling for attaching the motors to the screws. The whole set comes to about $130

So this brings me to about $1000 very quickly!! Well no budget survives first contact with a project and my project is no different. Realistically i'm building a rapid prototyper of superior quality compared with the makerbot models which sell for $2500 so long as i do not spend that much i'll be happy!

Start!

This is the first blog post. I intend to to record this summer 2011 as I attempt to construct a rapid prototyper.

A rapid prototyper is a machine capable of constructing any form of geometry from a 3d cad file, anything that you can draw can be "printed" in 3d using one of these machines. There are many different types of machine that come under the heading of rapid prototyper, I will be building a machine that constructs parts by melting plastic and then extruding the plastic out of a fine nozzle to build the parts I want.

This type of machine is complicated I will be using electronic parts from Makerbot, this is a company that produces hobby level rapid prototypers. (Buying one off the shelf would be no fun.) I will be design the mechanical layout myself and using off the shelf bearings and lead screws etc available over the net or via ebay.